Semi-permanent, yes. You often see someone tinkling away at it when you walk through.
I spent about half an hour this afternoon playing that great piano
Fabulously out of tune (even more so than when Valentina played it) and uneven sound and action, not to mention a couple of missing keytops (but I've played on much worse), and the 'practice pedal' was in the locked down position when I got to it, so I assume that it's only allowed to be released when a virtuoso like Lisitsa, by prior arrangement, came to perform.
Still, that allowed me to bang out my pieces - starting with a Chopin waltz, then the Schumann/Liszt Widmung, then Brahms, Mozart and Schubert - without drowning out the tannoy announcements. No need for subtlety in a noisy and busy train station, but a few people stayed round to listen, and even applauded....and a couple of elderly ladies asked me for some Schubert, so I obliged with the Impromptu D899/4, which happened to be the only Schubert I can play from memory.
Despite playing fortissimo much of the time, my hands got colder and colder (it was snowing outside - yes, it does snow in London, even in March....), so I stopped before my fingers seized up.